diff --git a/node_modules/architect-build/build_support/mini_require.js b/node_modules/architect-build/build_support/mini_require.js
index 8d4c219c..7af78f24 100644
--- a/node_modules/architect-build/build_support/mini_require.js
+++ b/node_modules/architect-build/build_support/mini_require.js
@@ -282,7 +282,13 @@ config.packages = Object.create(null);
 config.paths = Object.create(null);
 config.baseUrl = "";
 
-require.undef = function(module, callback) {
+require.undef = function(module, recursive) {
+    if (recursive) {
+        var root = (module + "/").replace("//", "/");
+        $undefAll(root, define.errors);
+        $undefAll(root, define.loaded);
+        $undefAll(root, define.modules);
+    }
     module = normalizeName("", module);
     var path = require.toUrl(module, ".js");
     delete define.errors[module];
@@ -291,6 +297,12 @@ require.undef = function(module, callback) {
     delete define.fetchedUrls[path];
 };
 
+function $undefAll(module, hash) {
+    for (var i in hash)
+        if (i.lastIndexOf(module, 0) == 0)
+            require.undef(i);
+}
+
 require.MODULE_LOAD_URL = MODULE_LOAD_URL;
 
 require.toUrl = function(moduleName, ext, skipExt) {
diff --git a/plugins/c9.ide.plugins/loader.js b/plugins/c9.ide.plugins/loader.js
index 6d8791af..144c79e2 100644
--- a/plugins/c9.ide.plugins/loader.js
+++ b/plugins/c9.ide.plugins/loader.js
@@ -239,7 +239,7 @@ define(function(require, exports, module) {
             paths[config.packagePath] = config.staticPrefix;
 
             requirejs.config({ paths: paths });
-            requirejs.undef([config.packagePath, "__installed__.js"].join("/"));
+            requirejs.undef(config.packagePath, true);
 
             require([[config.packagePath, "__installed__"].join("/")], function(installed) {
                 callback(null, installed);